A/B Control Logix / indirect file addressing

[PATL01]

I am currently converting a Softlogix program to run in a Control Logix platform. The problem I am having involves "double Indirect" addressing. i.e. N[N7:0]:[N7:1]
The "pointers" (in the original program) are derived using "CPT" instructions.
I have done some research on multi-dimensional arrays, but so far I have been unable to find any real good examples. (or even very many bad examples )
1 issue is the size that would be required of the array(s), i.e N7:0 could contain a value as high as 1264 (causing the pointer to look at N1264) and the word pointer (N7:1)can have a value of up to 1800. I know that I can make the arrays by calculating the Min/Max values that are used as pointers. I am really needing some examples, so I can see the Syntax.
If anybody knows where I could find some good A/B 5555 examples that use this type of addressing, I would appreciate it.
P.S. Before anyone suggests it, I will mention that I have talked with A/B~Rockwell tech support about this issue at great length.
Thanks in advance
Pat

 

[Macbeth]

You seem to be looking for a 1.2k dimensional array routine that has N7:0 as the Table Array dimension and N7:1 as the Data pointer. You indicate that the Array is 1264 x 1800 so then you need 2,275,200 Data Cells 16 bits wide for a total of 36.4m of memory?

This seems large for a PLC to handle. Can you explain your need for so much data in a PLC? Maybe there is an easer solution. Sorry I don't have any examples of that size to send this week, but these tech notes at this time is all I can offer.

Did you read this?
Indirect file addressing is not directly supported in the ControlLogix processor.
You can use a two dimensional array to simulate indirect file addressing.

http://domino.automation.rockwell.c...ED9883822C14F96D85256AFB006A155A?OpenDocument

Also read this.

http://domino.automation.rockwell.c...DFDD02E63607B17085256AFB006806A2?OpenDocument

http://domino.automation.rockwell.c...7AED6A2279835DF985256AFB006D9F0F?OpenDocument

 

[PATL01]

Thanks Macbeth, I had missed the 1st document while looking through the A/B knowledgebase.
As far as the Array Size is concerned, I can make the arrays managable by going through the existing pointers, and figuring out the Min/Max values. It is time consuming but it can be done.
The Softlogix platform allowed the original programmer to allocate huge amounts of memory for future expansion, but obviously this much memory is not being used currently.
I would still be interested in seeing any examples of 2 dimensional arrays,and how they actually are entered in the RLL, so that I can look at the Syntax.
I am fairly new to the Control Logix, and in all honesty I much prefer the old "image table" style of memory orginization. This is only because I am used to it
Thanks again
Pat

 

[jonesy29847]

I wsould like to suggest you look into ST programming for the the arrays. You may find the code easier to develop.